At present, many rocket experimenters are playing with various liquid fuel devices, [sciencish] is one of them. For safety reasons, he was tired of using pneumatic fuel delivery system in the experiment and decided to create something closer to mature rocket design. The result is a 3D printed turbopump for fuel delivery.
This design is no different from the turbocharger in the car. On one side, the turbine is rotated by compressed air supplied by the oil tank or compressor. The turbine is fixed on the same shaft as an impeller, which sucks in and pumps out the fuel and, ideally, sends it into the combustion chamber of the rocket. All this is made of resin printed parts, which makes it easy to create the fine geometry of the turbine and impeller.
The turbopump operates in 80 psi compressed air and can deliver 1.36 litres of water or alcohol fuel per minute. Unfortunately, however, this first stroke design can only provide 20 psi fuel pressure, which [sciencish] suspects is not enough to offset the combustion chamber pressure in his rocket design. More work is needed to raise this figure. However, with nozzles and ignition sources, it does produce some huge flames.
In general, the safety benefits of this turbopump come from the fact that the fuel remains separated from the oxidant before reaching the combustion chamber. Such systems are much less likely to cause a fire or explosion than systems that store air pressurized fuel.
Although the design has not reached the standard of rocket use, it is still effective. We doubt that the project should be promoted rapidly with some improvements in tolerance and fin design.
If you prefer solid rockets, we also have many such features. Video after break.